Increasing coastal change leads to mixed fortunes for wildlife

Newcomers such as the triggerfish are on the increase but coastal change could put puffins, terns and the Glanville fritillary butterfly at risk. 

Our experts have revealed a list of six species that might be seriously affected by our ever changing coastline due to coastal erosion and climate change. 

Research shows how an increasingly dynamic coastline could radically change the face of wildlife on our coast in the coming decades.   

The next century will see rising sea levels with the 8,050 miles (12955 km) of UK coastline going through a process of accelerated and immense change.  Increasingly, extreme weather events will potentially lead to huge turmoil for wildlife along this much loved habitat where millions of us spend the summer months.

David Bullock, Head of Nature Conservation at the National Trust, says: “The coast is at the forefront of how a changing climate will affect wildlife in the UK and is very vulnerable to the forces of change.  

 “Over the past decade we’ve been developing a better understanding of the coastline that we care for and in particular the 50 per cent that will be affected by increased coastal erosion or flooding in the future. 

“Our six coastal ‘canaries in the mine’ indicate how plants, animals and ourselves will have to live with an increasing rate of environmental change.”

The UK coastline is already being affected by rising sea levels and projections suggest that by 2100 sea levels will be more than half a metre higher than at present and increased erosion, with the British Geological Survey reporting a four-to-five-fold increase in the number of landslides during July and December 2012 in comparison with previous years.

But warming seas and the increased unpredictability of weather could also have a radical impact on coastal habitats and wildlife. 

Matthew Oates, the Trust’s National Specialist on Nature and Wildlife, says: “Climate change could change the face of our coastal flora and fauna.  With rising sea levels, our rich mud flats could simply disappear.

“Wildlife which relies on the gradual erosion of soft rock cliffs or lives on loose sand and shingle habitats could be caught out by an increasingly mobile landscape as a result of extremes in weather.

“Extreme weather will be a big factor.  We’re seeing more and more superlatives – the hottest, coldest, wettest or driest months on record.  Even on hard rock cliffs less affected by increased erosion, we are likely to see the boom and bust of more specialist plants and animals, as they suffer from increased flooding, salt deposition or drought stress.  Unfortunately there may be more bust than boom.”

Six species to watch

Little tern      

Little tern © Joe Cockram

Little tern © Joe Cockram

Little terns nest in loose colonies on sand and shingle beaches such as Blakeney Point, just above the high tide line.  This makes their nests very vulnerable to exceptional high tides and summer storms, which are likely to become more frequent due to climate change.  Winter storms and higher rates of beach erosion can also mean that places where they nested last year are no longer suitable when they migrate back to the UK each spring.

Little terns nest on National Trust managed land at:

  • Blakeney Point, Norfolk
  • Long Nanny, Northumberland

 

Puffin

Puffins on the Farne Islands © Joe Cornish/NTPL

Puffins on the Farne Islands © Joe Cornish/NTPL

Puffins are a great indicator of how human factors and climate change have an impact on the whole coastal ecosystem.  A combination of overfishing and warming seas has led to the bony and indigestible snake pipefish, scarcely found in our waters ten years ago, moving north to replace the puffins’ main food source, the sand eel.  Puffin chicks have occasionally been found dead, having choked trying to swallow pipefish.

Last summer’s wash-out saw a number of puffins’ burrows flooded, whilst an exceptionally harsh winter and spring storms this year led to the worst bird wreck in 50 years, with hundreds of puffins, guillemots, and razorbills washing up dead along the north-east coast, presumed to have starved in the difficult conditions.

These recent events have, however, been followed by summer success, with the five-yearly puffin count on the Farnes revealing that, although numbers are not as high as their peak in 2003, they are up by 8% on the 2008 figures, with just under 40,000 (39,926) pairs of nesting puffins.

You can find puffins on National Trust land at:

  • The FarneIslands, Northumberland
  • Lundy Island, Devon 

Oysterplant

Oysterplant © Cliff Henry

Oysterplant © Cliff Henry

Many coastal plants have adapted to survive in a range of environmental conditions.  But they are now threatened by the increased mobility of cliffs and dunes, coastal squeeze, increased drought stress, increased salinity, and increased length of time underwater.

The oysterplant is one example of a plant at risk. Now nationally scarce and appearing on the current IUCN Red List of Threatened Species in the near-threatened category, the oysterplant grows on exposed shingle beaches along the north-west coast of England and Scotland, as well as in Northern Ireland, where it is legally protected.  Like other coastal plants such as the yellow-horned poppy, it requires some disturbance to maintain its open shingle habitat, but extreme storms could wash it away completely.

Most population losses have been at the southern end of its range, due to extreme storms, excessive recreational pressures, coastal squeeze and removal of shingle from beaches.  However, as its seeds can be dispersed over long distances by the sea, there is the potential for it to spread and colonise new sites.

This plant can be found on National Trust land at:

  • Giant’s Causeway, Northern Ireland

Triggerfish

Warming seas have led to an influx of invasive non-native species on our shores, such as zebra mussels and japweed, which can proliferate on boats, jetties, and in rock pools, able to survive in increasingly moderate sea temperatures.

Perhaps most striking, however, are the occasional sightings of new natives such as the grey triggerfish off the coast of North Wales. Normally found in the warmer waters of the Atlantic and Mediterranean, the triggerfish’s appearance off the Welsh coast gives a taste of how our marine ecosystems could see profound changes in coming years.

The National Trust property nearest to where triggerfish have been found is:

  • Porthdinllaen, Wales

Glanville fritillary butterfly

Glanville fritillary © Matthew Oates

Glanville fritillary © Matthew Oates

The Glanville fritillary is a butterfly which exemplifies the boom and bust nature of coastal wildlife. Once found as far north as Lincolnshire, it has become restricted to the coastal landslips on the south-west coast of the Isle of Wight, pushed out by intensive farming which limits its caterpillar’s main food source, ribwort plantain.

Like many species which live on our coasts, it relies on highly specialised conditions – a gradually eroding, warm, south-facing cliff, with only the first stages of colonisation by plants. The greatest threats to its habitat therefore include the overstabilisation of cliffs through invasive plant species, and habitat loss through coastal squeeze.  But increased erosion could also make cliffs too unstable for the vegetation it depends on – and with unpredictable weather caused by climate change we could lose it from our shores completely.

Conversely, if climate change leads to warmer weather, the Glanville fritillary could recolonise the mainland from the Isle of Wight.

You can find this insect on National Trust land at:

  • ComptonBay, Isle of Wight

Cliff tiger beetle

Cliff tiger beetle © Andrew Whitehouse/Buglife

Cliff tiger beetle © Andrew Whitehouse/Buglife

Although it is a hunter, the cliff tiger beetle depends on a very specific habitat. It relies on relatively large areas of bare clay being exposed through cliff slumps and slippages, living beside wet seepages along the bare cliff face.

Two of its greatest threats are coastal development and the overstabilisation of soft cliffs (whether natural or human induced). And the increased mobility of cliffs this spring followed by hot weather this July has helped it.  But it is vulnerable to catastrophic events in the few places that it does survive.  Like many insects, the cliff tiger beetle lacks the ability to move if conditions suddenly become unfavourable.  It is only capable of short flights, so if it is lost from an area it may be difficult for it to recolonise.

These beetles live on coastal cliffs on National Trust land in:

  • West Dorset

Due to the recent mobility of cliffs on the Dorset coast, we strongly recommend that people do not put themselves at risk looking for cliff tiger beetles. The stability of a cliff face can be deceptive, and remember that the cliff tiger beetle relies on a degree of coastal instability to survive.

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